It's most likely a compatibility issue in the game itself. I run all of my games from the internal HD except for the ones that require the "black screen fix" with multiman. Try using MultiMan instead of Gaia to see if your compatibility improves.

agreed, use multiman v 1.15.05, if running form ext. hd make sure the game has no 4+gb files. If it does , simpily use split4g to to split those files into 2 parts so they will boot from external hdd! thats pretty much it!

no its well known and documented. ANY & EVERY game where you have to split the files to put them on an external, need the files rejoined to make them playable which means transferring them to the internal hard drive.

Easyiest way to tell is if a game has a file over 4GB in size it'll need to be on the internal drive to play.